I seem to be having a hard time getting my PH down from 8.0 . I have been doing RO/DI water changes and I have been able to get my KH from 9 down to 5 and my GH 15 down to 7. But my PH seems not to budge in my 125g and my 10g. My Tigers seem fine in my 10g and I have had them for approx 3 weeks now with no deaths. As for my crs out of the 15 I got a month ago I still have 10, 3 died 2 days after shipping and 2 are MIA. But in almost a month no deaths.

Since I have lowered my GH and KH my crs have turned more white. I also have 3 bcs that have been in my 125g tank for about 3 weeks and they too are showing more white. Even 1 of my bcs is berried so I'm hopping for the best. I have no crushed coreal, no lime stone in my tank that would keep my PH up so have even after the RO/DI WCs. I actually have several large to hugh pieces of drift would that should be lowering my PH cause they tuen my water a light tea color. I have no clue as to why my PH is still so high

Any help would be appreciated

What are you using to test you pH? Is it calibrated? Look into that first, because it sound like you pH is already lower.

I use Aquarium Pharmaceuticals test kit, both the high and normal test range.

Hmmm....can you calibrate them?